7-(substituted thioacylamino) cephalosporanic acid and derivatives thereof



United States Patent 3,365,449 7-(SUBSTITUTED THIUACYLAMINO) CEPH- ALOSPORANIC ACID AND DERIVATEVES THEREOF Tadayoshi Takano, Hirakata, Kiyoshi Hattori, Ibaragl, Kazuo Nakanishi and Kazuko Miura, Osaka, Surniuori Umio, Nishinomiya, and Teiji Kishimoto, Kyoto, Japan, assignors to Fujisawa Pharmaceutical Co., Ltd., Osaka, Japan, a company of Japan No Drawing. Filed Early 20, 1965, Ser. No. 473,515 Claims priority, application Japan, .Iuiy 23, 1964, 39/493,134 10 Claims. (Cl. 266-243) This invention relates to 7-(substituted thioacylamino) cephalosporanic acid and derivatives thereof, which compounds are useful as antimicrobial agents.

The compounds of this invention may be represented by the following general Formula I:

wherein R is lower alkyl, lower alkanoylamino, pyridyl, or aryl radical which is substituted or unsubstituted with halogen or nitro radical; R is an acetoxy or pyridinium group; X is oxygen or sulfur atom; Y is nitrogen atom or =CH; Z is CH or -CH *CH and M is hydrogen atom, a pharmaceutically acceptable non-toxic cation or an anionic charge.

As used herein the term lower is intended to mean groups containing one to six carbon atoms.

In the above Formula I, when R is aryl it includes phenyl, naphthyl, tolyl, etc. and it may be substituted with nitro or halogen atom such as chlorine, bromine, iodine, etc., and when M is a pharmaceutically acceptable nontoxic cation it includes, for example, an alkali metal ion such as the sodium or potassium ion, the ammonium ion and an organic quaternary ammonium cation such as triethylammonium, dicyclohexylammonium, diphenylenediammonium or dibenzylethylenediammonium.

The compound of Formula I of this invention may be prepared by reacting 7-arninocephalosporanic acid or a derivative thereof having the general Formula II:

o o o M n with a substituted thiocarboxylic acid having the general Formula III:

1 x (III) or a reactive derivative thereof, wherein R R X, Y, Z and M have the same as those described in Formula I.

Examples of the carboxylic acid of Formula III are in concrete,

2-acetamidothiazole-5- (Z-thioacetic acid), 2-acetamidothiazole-5-(S-thiopropionic acid), 2-methyl-1,3 ,4-oxadiazole-- (2-thioacetic acid), Z-methyl-1,3,4-oxadiazole-5-(3-thiopropionic acid), 2-ethyl-1,3,4-oxadiazole-5-(2-thioacetic acid),

"ice

2-ethyl-1,3,4-oxadiazole-5-(3-thiopropionic acid), 2-phenyl-1,3 ,4-oxadiazole-5-(Z-thioacetic acid) 2-phenyl-1,3,4-oxadiazo1e-5-(3-thiopropionic acid), 2-(3-chlorophenyl)-l,3,4-oxadiazole-5-(2-thioacetic acid), 2-(3-chlorophenyl)-1,3,4-oxadiazole-5-(3-thiopropionic acid), 2-(4-chlorophenyl)-1,3,4-oxadiazole-5-(Z-thioacetic acid), I 2-(4-chlorophenyl)-1,3,4-oxadiazole-5-(S-thiopropionic acid), 2-(3,4-dichlorophenyl)-1,3,4-0xadiazole-5-(2-thioacetic acid), 2-(3,4-dichlorophenyl)-l,3,4-oxadiazole-5-(3-thiopropionic acid), 2-(3,4,5-trichlorophenyl)-l,3,4-oxadiazole-5-(Z-thioacetic acid), 2-(3,4,5-trichlorophenyl)-1,3,4-oxadiazole-5-(3-thiopropionic acid), 2-(3-nitrophenyl)-l,3,4-oxadiazole-5-(Z-thioacetic acid), 2- 3-nitrophenyl) 1 ,3 ,4-oxadiazole-5- 3-thiopropionic acid), 2-( 4-nitrophenyl)-1,3,4-oxadiazole-5 -(2-thioacetic acid), 2-(4-nitrophenyl)-1,3,4-oxadiazole-5-(3-thiopropionic acid), 2- (3 -chloro-4-nitrophenyl -1,3,4-oxadiazole-5-(2-thioacetic acid), 2- 3-chloro-4-nitrophenyl) 1,3 ,4-oX-adiazole-5-( 3-thiopropionic acid), 2-pyridinyl-1,3,4-oxadiazole-5-(Z-thioacetic acid) Z-pyridinyl-1,3,4-oxadiazole-5-(3-thiopropionic acid),

and further each of the above compounds replacing thiazole and 1,3,4-0Xadiaz0le with 1,3,4-thiadiazole.

7-aminocephalosporanic acid (7-amino-3-acetoxymethyl-3-cephem-4-carboxylic acid) which is one of the starting materials of Formula II is a known compound and can be obtained by the hydrolysis of the antibiotic Cephalosporin C [Biochemical Journal, 79, 408-416 (1961)].

When using a substituted thiocarboxylic acid, the reaction is preferably carried out in the presence of a condensing agent such as dicyclohexylcarbodiimide, N-cyclohexyl-N-morpholinoethyloarbodiimide, pentamethyleneketene-N-cyclohexylimine, N-ethyl-o-phenyl-isoxazolium- 3-sulphonate or phosphorus trichloride, etc. Under such circumstances, it is believed that the reaction may mainly proceed through an active form of the carboxyl radical in the substituted thiocarboxylic acid or of the amino radical in the 7-aminocephalosporanic acid.

Examples of the reactive derivatives of the substituted thiocarboxylic acid to be frequently used are the acid halide, acid azide, mixed acid anhydride with alkylph0sphoric acid or alkylcarbonic acid, acid amide with imidazole or 4-substituted imidazole, acid cyanomethyl ester, acid p-nitrophenyl ester and so forth. These reactive derivatives are suitably selected in accordance With the kinds of the substituted thiocarboxylic acid to be used.

The reaction is usually carried out in the presence of a solvent. As a suitable solvent may be mentioned acetone, dioxane, acetonitrile, chloroform, ethylene chloride, tetrahydrofuran, or other organic solvents which are inert in the reaction and are used commonly. Of these solvents, the hydrophylic ones may be used with water.

Also, the reaction may be carried out in the presence of a base such as an alkali metal hydrogen carbonate, trialkylamine, pyridine, etc. The reaction is carried out in most cases under cooling or at room temperature though the temperature is not particularly limited.

After completion of the reaction, the reaction product is separated according to conventional methods known in the art.

When using the compound of Formula II wherein M is a pharmaceutically acceptable non-toxic cation as a starting compound, the object compound of Formula I wherein M is hydrogen is mainly obtained, because dissociation of the cation tends to occur during the separation of the reaction product. Therefore, if it is desired to obtain the object compound of Formula I wherein M is a pharmaceutically acceptable non-toxic cation, the compound of Formula I wherein M is hydrogen is treated with an appropriate compound such as sodium hydroxide, potassium hydroxide, sodium a-ethylhexanoate, triethylamine, dicyclohexylamine, diphenylenediamine or dibenzylethylenediamine.

In addition, the compound of Formula I wherein R is pyridinium may be obtained by reacting the compound of Formula I wherein R is acetoxy, with pyridine.

Both 7-aminocephalosporanic acid or a derivative thereof of Formula II to be used in the reaction of this invention and the product compound of Formula I are comparatively unstable and tend to decompose during the reaction. Therefore, it is preferable to carry out the reaction and separation under mild conditions.

The resulting compound of Formula I not only demonstrates resistance to penicillinase and an acid, but exhibits advantageous physiological properties and activity against a wide variety of micro-organisms.

The following examples will illustrate the compounds available in accordance with this invention.

In the examples, MIC means a minimum inhibitory concentration which is measured by the serial dilution method commonly employed in bioassay of antimicrobial compounds, and Escherichia coli and Staphylococcus aureus are referred to as E. coli and St. anreus, respectively.

EXAMPLE 1 (i) 7- [2-acetamididothiazole-S-(Z-thioacetamido)] cephalosporanic acid To 685 mg. of 7-aminocephalosporanic acid in 1.4 cc. of triethylamine and cc. of chloroform were added 590 mg. of 2-acetamidothiaZole-5-(Z-thioacetic acid) and 320 mg. of dicyclohexyl-carbodiimide and allowed to stand for two days at room temperature. The reaction mixture was condensed under reduced pressure. The remainder was adjusted to pH 2.2 with hydrochloric acid and extracted with ethyl acetate. From the extract solution, ethyl acetate was distilled off under reduced pressure to obtain 115 mg. of 7-[2-acetamidothiazole-5-(2- thioacetamido)] cephalosporanic acid as powders having M.P. 150 C. (dec.).

MIC: E. coli /00., St. aureus 2.0 7/00.

(ii) 7-[Z-acetamidothiazole-S-(Z-thioacetamido) ]-3- pyfiidiniummethyl-deceplzalosporanic acid inner salt The substance (80 mg.) obtained in (i) dissolved in 1 cc. of water and 0.5 cc. of pyridine was allowed to stand overnight and condensed under reduced pressure. The remainder was dried and thoroughly washed with acetone. The resulting precipitate dissolved in water Was filtered and condensed under reduced pressure. The remainder (30 mg), washed with acetone and dried, was added to 3 cc. of an anion exchange resin [Dowex 1 x 8 (acetate type)], and filtered. The filtrate was condensed under reduced pressure to obtain 8 mg. of 7-[2-acetamidothiazole-S-(Z-thioacetamido)] cephalosporanic acid as powders having M.P. 100 C. (dec.).

UV: i5 5; 264 m,., E 179,

xfigf 276 my, E 174. MIC: E. coli 40 /00., St. aurous 2 7/00.

EXAMPLE 2 7- [Z- JhcnyI-I ,3,4-llziadiaz0lc-5-(Z-lhioacctamido)] celphalosporanic acid CH2OCOCHa Z-phenyl-l,3,4-thiadiazole-5-(2-thioacetic acid) (227 mg.) was dissolved in 10 cc. of tetrahydrofuran and 1 cc. of tetrahydrofuran solution containing 200 mg. of dicyclohexylcarbodiimide and stirred for 15 minutes at room temperature. To this solution was added dropwise 250 mg. of 7-aminocephalosporanic acid in 0.3 cc. of tricthylamine and 6 cc. of chloroform within a minute, and allowed to stand overnight after stirring for five hours and a half. The reaction mixture was filtered and then tetrahydrofuran was distilled oil under reduced pressure. To thus obtained remainder, water was added. The solution was adjusted to pH 3.0 with 5% hydrochloric acid and extracted with cc. of ethyl acetate after removal of the oily decomposed product of dicyclohexylcarbodiimide. From the extract, ethyl acetate was distilled off under reduced pressure and the remainder was dissolved into acetone and filtered. Acetone was then distilled oif from the filtrate and the remainder was washed with petroleum ether to obtain 29 mg. of 7-[2-phenyl-1,3,4- thiadiazole-S-(Z-thioacetamido)] cephalosporanic acid as powders having M.P. l23 C. (dec.).

UV: AQQZQP 300 m E 221.

MIC: E. c0li 40 7/00., St. aurcns 2 7/00.

EXAMPLE 3 To 560 mg. of 7-aminocephalosporanic acid in 20 cc. of chloroform and 0.8 cc. of triethylamine were added 510 mg. of 2-(4-pyridyl)-l,3,4-thiadiazole-5-(2-thioacetic acid) and 320 mg. of dicyclohexylcarbodiimide in 7 cc. of acetone. The solution was stirred for 20 minutes at 40 C. and then 2 hours under ice-cooling, and allowed to stand overnight at room temperature. The reaction mixture was condensed to half in its volume under reduced pressure and extracted with ethyl acetate after adding sodium hydrogen carbonate. The water layer was adjusted to pH 2.8 to obtain a precipitate. The precipitate obtained was washed with ethyl acetate and extracted with acetone, and then acetone was distilled oif under reduced pressure from the extract. The remainder was washed with ether to obtain mg. of 2-[2-(4-pyridy1)- i. J 1,3,4-thiadiazole-5-(2 thioacetamido)] cephalosporanic acid as powders having M.P. 165 C. (dec.). UV: fiZ 316 my, 172.

6 EXAMPLE 6 7- [2-plzenyl-I,3,4-0xadiaz0le-5-(S-thiopropionamido)] cephalosporanic acid MIC: E. cli 40 7/00., St. aureus 20 7/60.

EXAMPLE 4 -L -s-om-omooNH 7-[Z-methyl-l,3,4-0xadiazole-5-(Z-thioacetamido)] L L cephalosporanic acid CHEOCOCH JOOH I I To 500 mg. of Z-phenyl-1,3,4-oxadiazole-5-(3-thiopropionic acid) and 430 mg. of dicyclohexylcarbodiimide in 0 l i 20 cc. of chloroform was added 540 mg. of 7-aminoceph- 0 OH2OCOCH3 alosporanic acid in 0.5 cc. of triethylamine and 15 cc. of chloroform. The solution was stirred for 5 hours at (EOOH room temperature and allowed to stand overnight. After allowing to stand, the reaction mixture was filtered and the filtrate was condensed under reduced pressure. The 6 2- eth l-1,3,4- xad a ole-S- 2-th1oacetic aci d lii itfbf l ilor form w as at id ed 2.4 cc. of tetrai i after adqmg was ad]uste.d to PH hydrofuran solution containing dicyclohexylcarbodiimide Wan hydrochlonc .acld and extracted with ethyl (2.15 gjlo cc.) This Solution was further a d d e d drop by tate. This extract solut on was condensed under reduced drop with 680 mg. of 7-aminocephalosporanic acid in 20 pressure and f h i to 011mm 9 of g cc. of chloroform and 0.8 cc. of triethylamine at room l i' lam 2 Cep temperature. This mixture was stirred for 3 hours and D Spmamc acld as powders havmg 89-97 allowed to stand overnight. After allowing to stand, tetra- U 2 33; C2H5OH-NaOH 2 m, E 257 hydrofuran and chloroform was distilled off under reduced I pressure. An oily substance obtained was filtered off after MIC: v aureus alkalifying with sodium hydrogen carbonate. The filtrate EXAMPLE 7 was adjusted to pH 1.0 with 5% hydrochloric acid and a extracted with ethyl acetate. From the extract, ethyl acetate (1) 7' 253;255:5 2 25;; fffgi z i (2 was distilled off under reduced pressure, and the remainder p p was washed with ether to obtain 13 mg. of 7-[2-methyl- 1,3,4 oxadiazole 5-(2-thi-oacetamido)] cephalosporanic 35 i j g acid as powders having M.P. SO -86 C. (dec.). 3*" O S OH1CONH] 1 W MIC: E. coli 20 'y/cC., St. aureus 1 'y/cc. CI-120000113 EXAMPLE 5 40 O OH [2 phenyl 134 oxadiazole 5 (2 thi0acemmid0)] 2-( 4-nitrophenyl) -1,3,4-oxadiazole-5-(2-thioacetic acid) cephalospomnic acid (603 mg.) was dissolved in 30 cc. of chloroform and 2 cc. of tetrahydrofuran solution (215 trig/cc.) and stirred for 30 minutes at room temperature. To this solution was added dropwise 680 mg. of 7-aminocephalosporanic acid in LL ii S 0.7 cc. of triethylamine and 15 cc. of chloroform. This J obtained solution was stirred for 4.5 hours at room tem- N CH2OC OCHS perature and then allowed to stand overnight. The reaction mixture was filtered and then chloroform was distilled OH off from the filtrate under reduced pressure. The remainder was filtered after adding water, and the filtrate was ad- T 5 f7 p h 1 15 f justed to pH 2.0 with hydrochloric acid and extracted 9 0 0 fi 0 with ethyl acetate. The extract solution was condensed chloloform and Of tnethylammehwas added 5 under reduced pressure, and the remainder was dissolved of chloroform} 3 480 of in acetone. This acetone solution was also condensed under gggzg g 'g zig23 32;? z gt ii i igi 2x23 521 reduced pressure, and the resultant remainder was Washed with ether to obtain 144 mg. of 7-[2-(4-nitrophenyl)-1,3,4-

as owers .ec.. with acetone to obtain 119 mg. of 7-[2-phenyl-1,3,4-oxadip 807 C H OH NaOH azole-S-(S-thioacetamido)] cephalosporanic acid as crys- UV: Matti. 2 5 2615 u, E 369. tals havmg 117-122 MIC: E. coli 40 /00., St. aureus 1 /00. UV: A5333; C3H5OH-N8OII 272 E 439. (ii) Dicycylohexylamz'ne salt 0] 7[2-(4-nitr0phenyl)- 1,3,4-0xad' 0! -5- 2-th'0 et id MIC: E. colt 20 7/00., St. aureus 0.4 'y/cc. add laz e 1 ac am 0)] cephalospommc N-N NOr- LOJ-S-CH2C oNrr-f V (31120 C 0 CH3 The substance (90 mg.) obtained in (i) was dissolved in 4 cc. of acetone. To this acetone solution was added 30.5 cc. of dieyclohexylamine and allowed to stand in an ice-box to obtain 38 mg. of dicyclohexylamine salt of 7 [2 (4 nitrophenyl)-1,3,4-oxadiazole-5-(2-thioacetamido)] eephalosporanic acid as crystals having M.P. 170- 177" C. (dec.).

UV: AEZg 310 m,., E 210,

EXAMPLE 8 (i) 7-[2-(3-cizl0r0phenyl)-1,3,4-0xadiazole-5-(2- thioacctamido) ccphalosporanic acid 1 COOH 2-(3-chlorophenyl)-1,3,4-oxadiazole (2 thioacetic acid) (813 mg.) was dissolved in cc. of chloroform and 3 cc. of tetrahydrofuran, to which solution was added 4 cc. of tetrahydrofuran solution of dicyclohexylcarbodiimide (211 mg./cc.) and stirred for 5 minutes at room temperature. To this solution was further added 820 mg. of 7-aminocephalosporanic acid in 0.8 cc. of triethylamine and 15 cc. of chloroform and stirred for 5 hours at room temperature. After allowing to stand overnight in an icebox, the reaction mixture was filtered, and the filtrate was condensed under reduced pressure. The remainder was added with 10 cc. of water and filtered. The filtrate was adjusted to pH 2.0 with hydrochloric acid and extracted with ethyl acetate. The extract solution was condensed under reduced pressure, and the remainder was washed with petroleum ether to obtain 193 mg. of 7-[2-(3-chlorophenyl)-1,3,4-oxadiaz0le-5-(2-thioacetamido)] cephalosporanic acid as powders having M.P. 86-93 C. (dec.).

V Atgklihydmfumn m, E

MIC: E. coli /ee., St. aureus 0.5 /cc.

(ii) Sodium salt of 7-[2-(3-chl0r0phenyl)-1,3,4-0xadiaz0lc-5-(Z-thfoacetamido)1 ceplialosporanic acid UV: W 269 m E 368,

A1 299 m.., E 100.

MIC: E. coli 40 'y/CC., St. aureus 1 /cc.

We claim: 1. A compound of the formula,

in which R is lower alkyl, lower alkanoylamino, pyridyl, phenyl or phenyl having nitro or halogen; R is acetoxy or pyridinium; Y is oxygen or sulfur; Z is CH or CH CH and M is hydrogen, an alkali metal, dicyclohexylammonium or an anionic charge.

2. 7-[2-phenyl-1,3,4-thiadiazole-5-(2 thioacetamido)] cephalosporariic acid.

3. 7-[2-(4-pyridyl)-1,3,4-thiadiazole 5 (Z-thioacetamido)] cephalosporanic acid.

4. 7-[2-methyl-l,3,4-oxadiazole-5-(2 thioacetarnido)] cephalosporanic acid.

5. 7-[2-phenyl-1,3,4-oxadiazole-5-(2 thioacetamido)] cephalosporanic acid.

6. 7-[2-phenyl-1,3,4-oxadiazole 5 (S-thiopropionamido)] eephalosporanic acid.

7. 7-[2-(4-nitrophenyl)-1,3,4-oxadiazole 5 (2-thioacetamido)] cephalosporanic acid.

8. 7-[2-(3-chlor0phenyl)-1,3,4-oxadiazole 5 (2-thioacetamido)] cephalosporanic acid.

9. Sodium salt of 7-[2-(3-chlorophenyl)-1,3,4-oxadiazole-S-(Z-thioacetamido)] cephalosporanic acid.

10. Dicyclohexylamine salt of 7-[2-(4-nitrophenyl)- 1,3,4-oxadiazole-5-(2 thioacetamido)] cephalosporanic acid.

References Cited UNITED STATES PATENTS 3,218,318 11/1965 Flynn 260243 3,261,832 7/1966 Cowley et al 260243 NICHOLAS S. RIZZO, Primary Examiner. 

1. A COMPOUND OF THE FORMULA 